Cytotoxic CD4⁺ T cells (CD4⁺ CTLs) represent a novel subset of T cells with cytotoxic effects. They recognize target cells in an antigen-specific manner, relying on class II major histocompatibility complex (MHC-II) interactions. CD4⁺ CTLs exert cytotoxic effects on target cells by secreting cytotoxic molecules such as granzymes, perforin, and granulysin. Recent studies have revealed their significant roles in various autoimmune diseases. This review focuses on the differentiation, phenotypic characteristics, and roles of CD4⁺ CTLs in different types of autoimmune disorders, aiming to provide new insights for the prevention and treatment of these diseases.
Humans ; Autoimmune Diseases/immunology* ; CD4-Positive T-Lymphocytes/immunology* ; Animals ; T-Lymphocytes, Cytotoxic/immunology* ; Perforin/immunology* ; Granzymes/immunology*

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon gene (STING) signaling pathway is a crucial component of the immune system. It detects abnormal cytosolic double-stranded DNA and promotes the expression of type I interferons and other inflammatory factors, thereby protecting the body from pathogenic infections. In children, an immature immune system or genetic mutations can lead to immune dysregulation, increasing the risk of autoimmune diseases (AID) and autoinflammatory diseases. Recent studies have shown that aberrant activation of the cGAS-STING signaling pathway is associated with the development of AID and autoinflammatory diseases in children. This review summarizes the research progress on the cGAS-STING signaling pathway in childhood AID and autoinflammatory diseases, aiming to provide new directions for clinical diagnosis and treatment.
Humans ; Nucleotidyltransferases/physiology* ; Membrane Proteins/physiology* ; Signal Transduction/physiology* ; Child ; Autoimmune Diseases/immunology* ; Inflammation/etiology*

Interleukin 24 (IL-24) is a member of the IL-10 cytokine family and is primarily synthesized by lymphocytes and activated monocytes. IL-24 exerts its immunological functions by interacting with membrane receptors or intracellular proteins, leading to the activation of Janus protein tyrosine kinase/signal transducer and activator of transcription (JAK/STAT), p38 mitogen-activated protein kinase (p38 MAPK), and endoplasmic reticulum stress pathways in target cells. This versatile cytokine has specific abilities to inhibit tumor proliferation and invasion, expedite wound healing, and contribute to cardiovascular protection. IL-24 is involved in the pathogenesis of various autoimmune and inflammatory disorders, presenting itself as a prospective therapeutic target for the treatment of such conditions. This article primarily delves into the role and mechanisms of IL-24 in physiological processes, aiming to provide novel insights and avenues for disease treatment.
Humans ; Animals ; Interleukins/physiology* ; Signal Transduction ; Endoplasmic Reticulum Stress ; p38 Mitogen-Activated Protein Kinases/metabolism* ; Neoplasms/metabolism* ; Autoimmune Diseases/metabolism* ; Inflammation/immunology* ; STAT Transcription Factors/metabolism* ; Janus Kinases/metabolism*

Allergy and Immunology ; Ambulatory Care ; Autoimmune Diseases/therapy* ; COVID-19 ; Communicable Disease Control ; Connective Tissue Diseases/therapy* ; Delivery of Health Care/methods* ; Dermatology ; Humans ; Immunosuppressive Agents/therapeutic use* ; Patient Selection ; SARS-CoV-2 ; Singapore ; Skin Diseases, Vesiculobullous/therapy* ; Telemedicine/methods* ; Tertiary Care Centers ; Vasculitis/therapy*

Aging is a complex process associated with dysregulation of the immune system and low levels of inflammation, often associated with the onset of many pathologies. The lacrimal gland (LG) plays a vital role in the maintenance of ocular physiology and changes related to aging directly affect eye diseases. The dysregulation of the immune system in aging leads to quantitative and qualitative changes in antibodies and cytokines. While there is a gradual decline of the immune system, there is an increase in autoimmunity, with a reciprocal pathway between low levels of inflammation and aging mechanisms. Elderly C57BL/6J mice spontaneously show LGs infiltration that is characterized by Th1 but not Th17 cells. The aging of the LG is related to functional alterations, reduced innervation and decreased secretory activities. Lymphocytic infiltration, destruction, and atrophy of glandular parenchyma, ductal dilatation, and secretion of inflammatory mediators modify the volume and composition of tears. Oxidative stress, the capacity to metabolize and eliminate toxic substances decreased in aging, is also associated with the reduction of LG functionality and the pathogenesis of autoimmune diseases. Although further studies are required for a better understanding of autoimmunity and aging of the LG, we described anatomic and immunology aspects that have been described so far.
Aged ; Aging ; Allergy and Immunology ; Animals ; Antibodies ; Atrophy ; Autoimmune Diseases ; Autoimmunity ; Cytokines ; Dilatation ; Eye Diseases ; Humans ; Immune System ; Inflammation ; Lacrimal Apparatus ; Mice ; Ocular Physiological Phenomena ; Oxidative Stress ; Pathology ; Tears ; Th17 Cells

Objective To explore the clinical characteristics of autoimmune disease with dual seropositive antibodies of leucine-rich glioma inactivated 1(LGI1)and contactin-associated protein 2(Caspr2).Methods The clinical data of seven patients with dual seropositive LGI1 and Caspr2 antibodies who were admitted to the Neurology Department of Peking Union Medical College Hospital from July 2014 to December 2017 were retrospectively analyzed.Results Central,peripheral and autonomic nervous systems were all involved in the seven cases;100%(7/7)presented with insomnia,myokymia,neuropahic pain and hyperhydrosis;71%(5/7)showed memory decline or psychiatric and behavioral symptoms;57%(4/7)had urinary hesitation or constipation;and 43%(3/7)had seizure.Electromyography showed 100%(6/6) of the patients had prolonged afterdischarges following normal M waves and/or abnormal spontaneous firing.Electroencephalography revealed slow waves or basic rhythm slowing in 71%(5/7)of patients.Electrocardiography showed sinus tachycardia,axis deviation,and prolonged QT intervals in 71%(5/7)of patients.One patient died from arrhythmia before immunotherapy.One died from pulmonary infection after immunotherapy.Improvement with immunotherapy was documented in the other five cases.No relapse was noted during the 1-2-year follow-up.Conclusions Autoimmune disease with dual seropositive antibodies of LGI1 and Caspr2 can diffusely affect the central,peripheral,and autonomic nervous systems.The possibility of this disease should be considered in patients with acute and subacute onset of neuropsychiatric symptoms,especially in patients with accompanying insomnia,myokymia,and hyperhydrosis.
Autoantibodies ; blood ; Autoimmune Diseases ; immunology ; Humans ; Membrane Proteins ; immunology ; Nerve Tissue Proteins ; immunology ; Proteins ; immunology ; Retrospective Studies

FcγRIIB, the only inhibitory IgG Fc receptor, functions to suppress the hyper-activation of immune cells. Numerous studies have illustrated its inhibitory function through the ITIM motif in the cytoplasmic tail of FcγRIIB. However, later studies revealed that in addition to the ITIM, the transmembrane (TM) domain of FcγRIIB is also indispensable for its inhibitory function. Indeed, recent epidemiological studies revealed that a non-synonymous single nucleotide polymorphism (rs1050501) within the TM domain of FcγRIIB, responsible for the I232T substitution, is associated with the susceptibility to systemic lupus erythematosus (SLE). In this review, we will summarize these epidemiological and functional studies of FcγRIIB-I232T in the past few years, and will further discuss the mechanisms accounting for the functional loss of FcγRIIB-I232T. Our review will help the reader gain a deeper understanding of the importance of the TM domain in mediating the inhibitory function of FcγRIIB and may provide insights to a new therapeutic target for the associated diseases.
Autoimmune Diseases ; drug therapy ; genetics ; immunology ; Humans ; Protein Domains ; Receptors, IgG ; chemistry ; immunology

Systemic lupus erythematous (SLE) is a systemic autoimmune disease with multi-organ inflammation caused by the production of pathogenic autoantibodies and immune complexes reflecting a global loss of tolerance. Lupus nephritis (LN) is present in approximately 60% of SLE patients and is considered a major predictor of a poor prognosis. To date, many studies utilizing genomics, transcriptomics, epigenetics, metabolomics, and microbiome have been conducted on a range of animal models and lupus patients to understand the pathogenesis of SLE and LN. Collectively, these studies support the concept that LN is caused by increased cell death, which has not been properly dealt with; abnormal innate immunity; hyperactive adaptive immunity; and genetic variants triggered by a range of environmental factors. This review summarizes the results from studies that contributed strongly to elucidating the pathogenesis of SLE and LN, highlighting the immunological and non-immunological mechanisms.
Adaptive Immunity ; Allergy and Immunology ; Antigen-Antibody Complex ; Apoptosis ; Autoantibodies ; Autoimmune Diseases ; Cell Death ; Epigenomics ; Genomics ; Humans ; Immunity, Innate ; Inflammation ; Lupus Nephritis* ; Lymphocytes ; Metabolomics ; Microbiota ; Models, Animal ; Prognosis ; Wolves*

The liver has been characterized as a frontline lymphoid organ with complex immunological features such as liver immunity and liver tolerance. Liver tolerance plays an important role in liver diseases including acute inflammation, chronic infection, autoimmune disease, and tumors. The liver contains a large proportion of natural killer (NK) cells, which exhibit heterogeneity in phenotypic and functional characteristics. NK cell activation, well known for its role in the immune surveillance against tumor and pathogen-infected cells, depends on the balance between numerous activating and inhibitory signals. In addition to the innate direct "killer" functions, NK cell activity contributes to regulate innate and adaptive immunity (helper or regulator). Under the setting of liver diseases, NK cells are of great importance for stimulating or inhibiting immune responses, leading to either immune activation or immune tolerance. Here, we focus on the relationship between NK cell biology, such as their phenotypic features and functional diversity, and liver diseases.
Adaptive Immunity ; Animals ; Autoimmune Diseases ; immunology ; Humans ; Immune Tolerance ; Immunity, Innate ; Killer Cells, Natural ; immunology ; Liver Diseases ; immunology ; Mice

Vav1, as a key downstream signaling molecule of T cell receptor, includes a catalytic core DH-PH-ZF domain with the function as guanine nucleotide exchange factor (GEF), and a SH3-SH2-SH3 domain with the function as adaptor protein. These two structures of Vav1 play different roles in the development, activation, proliferation and function of T cells, and thereby exert the different regulatory effect on the occurrence and development of autoimmune disease, graft rejection, cancer and other clinical conditions, implicating that Vav1 might be a potential therapeutic target for these diseases. This paper reviews the role of Vav1 in T cells and the occurrence of related diseases.
Adaptor Proteins, Signal Transducing ; Animals ; Autoimmune Diseases ; genetics ; physiopathology ; Humans ; Neoplasms ; genetics ; physiopathology ; Proto-Oncogene Proteins c-vav ; chemistry ; immunology ; metabolism ; T-Lymphocytes